Construction of circular saws



Nov. 11, 1958 c.'c. HUGHES consmucwxon 0F CIRCULAR SAWS Origin a1 Filed July 1, 1954 INVENTOR. 61. m: C. Hume 5s Re. 24,562 Reissued 'Nov. 1 1 1 958 United States Patent ()liiice h 4 CONSTRUCTION OF CIRCULAR SAWS Clyde, Hughes, Arcadia, assignor toHughes Blades, Inc., Pasadena, Calif., a corporation of Caliv semis Original'NQ. 2,763,258; datetlsepternbei 18, 1956, Sena] No. 440,634, July 1,1954. Application foi-reissue' July 3,1958, Serial No. 747,558

15 Clainis. C1."125 15' Matter enclosed inlheavy brackets appears in the olfig'ilial Patient t iffll'msno part of this reissue specification; matter 'priu'ted"in italics indicates the additions made' by' reissue;

This invention is'dire'cteii' to improvements incircular saw construction and is particularly "deemed tocir'cula'r' saws pr'oyided'with a metallic'circular, distant-tweet substantially uniform thickness provided with an i interrupt'cd external edge, the segments of such edgefbeing providedwith cutting or abrading" segments for elements. In'accordance with the invention herein dis closed means" are provided 'forincreasing the life of such saws," for in creasing the'rapi'clity with which Lents can made 'there'- withand for preventing the individual cutting'elements or segments from being separated froi-n tlm core by the abrading and Wearingeffect' of cuttings Although the'inven't'ion may beapplied to a great variety ofcircularsawshaving cutting elements of variou s types', it'is of particularly utility when applied to circular saws provided with cutting segments composed ofor containing diamonds "of diamond chips. One form of a saw greatly benefited by the construction of this 1 invention emple 's diamond impregnated segments (made of diamonds'and powered metal, suitably compressed and sint'ered'to "form a uning elemem), these diamond impregnated cutting elemen ts' being then soldered or braze'rkontotl'ie edge-of nated cutting segments, it is essential that their llfe be pr'ol'ong'e'd'andthat the core be'capablef'of pr'operly supporting these segments throughout their entire life.

Circular saws provided with diamond impregnated segmerits are used extensively in cutting grooves'onslots'in concerete', such grooves or slots then acting" asexp'ansion crete contains very hard aggregate and sand as well as the-cementing compounds. The fine, sharp-edged particles 'of. sand and stone exert a pronounced and'dis'a'strous abrasive effect-upon the-disc-like core of thesaws; The" abrasive effect becomesmost'evident in thezone immedi ately adjacent the juncture of the diamond impregnated A further object'of the invention is to discloseand provide a circular saw comprising a disc-like core of suitable"- uniform thickness, cutting segmentsearried by the-edge of such core, and means carriedby the corefadjacentthesegments and projecting from the surfaces of the core for agitating arid-dischargingcuttings: j

Fig, 1 is a side elevation of a circular saw'embodying one form of the pr'esent invention. A

Fig. 2 is an enlarged radial section takenalong theplanejindi'cated by line 'III I of Fig. 1. 1

Fig.3 is a section taken alongr-the plane III-IIIof Figll. I

Fig 4 is a transverse fragmentaiy view takenin the same plane as FigTZ illustrating wear on a saw construe? rapidlvwe arin a zone immediately adjacejnt the inneror segment and the disc-like" core, reducing the thickness of v and rock Which appear to be'retainedior massed within" the'kerf and radially inward from the cutting segments.

Ar'i object of this invention' therefore is'to disclose and provide a saw construction including means whereby cuttings are agitated and "expelled from the kerfi 'the reby" reducing and minimizing the wear of the'core normally occasioned by such cuttings.

embodyinga modification of this invention.

tion not embodying this invention. p

.Fig. 5 isa fragmentary side view of a circular 'saw 13FigI'6 is a fragmen ary rahsverse section taken in the plane 'i'ndicat'ed' byline VI'V1 er Fig. 5. j v

The 's'a'vifillu'strated comprisesa disc-like circular core 10"" provided with a central arbor or opening-13. -'l "h e' core 10"is of virtually unifo rrn thiekness and hasiplanarsidesor surfaces 11 and12. Theicircumferential edge of 7 this core is periodically interrupted b yj radial slots such asslots 14, '15,16"and' the like. Theslots-may be of uniform widthor they may'te ri'iiinate in enlarged, areas thereto, asilversolderisindicatedat'fllf z a It hasbeen' found that in actual'practice these s aws soldeied edge of each ofth'e cutting 'seginents soas to resemble in cross"sectio'ri"theoutlineillustrated in Fig. j4.

It will be noted that the wear is inost'pronouncedabove the layer of solder thereby weakening the core and per: mitting the entire segment '17 to break 'off.

In accordance with the present invention, pins, studs; buttons'or inserts such as 26 and 27 are placed onthe surfaces 11 and 12 of the core immediately adjacent the edge and the cuttingelement or segment '17, these but tons projecting above the surface of the'core a distance'equivr alentto thethickness of the cutting segmentlf as'-in dicated in Fig.2. It Will'be'remembered that cores of a standard thickness, say 0.1 inch may carry segments which are 0.15" to 0.25" thick. The buttons or stud s 26, 27 should have their opposing faces spaced 'a distancesubstantially equivalent to the thickness offth e' cutting segment. 1 One 'or more of these buttons inay' be carried above each of t11e"segments '17', 18"'an"d the'likei In practice it hasbeen founddesirable to have theibut ton 'sgf studs or inserts adjacent the radial 'ed'ges"of theinwaril; ly extending slots such;as the"slot's 14, 15,16 and the likej Th' agitating buttons" or studs 26'," 27;' 'etc., arep'r'eferably made of metal although in someinstancies'theusei of rubber orrubber composition has been'fouiid sa'tisk", factory. It is to be noted that everitho'ugh the-care of? the saws is made of steel havin'g a Rockwell C tastiest" of 28 32,'the' abrasive particles'of sand and stone" rapidly Wear the steel away. The circumferentially' spaced but- Z tonsorstudsials o exhibitwear (when made frorn'rnetal) 'but'not to the same extentjand moreover, such buttons even though widely spaced, actually prevent theivearof. the core between such buttonson thesame sidebffthe T cor'e: Thbuttoris; studs 'or inserts appear to"act"as" way that the buttons 27 and 27 project).

agitating means which prevent the cuttings from compacting and instead discharge and flush the cuttings from the kerf. Rubber composition buttons appear to resist wear and also function as agitating and sc'avaging means.

The modified form of construction illustrated in Figs. and 6 contemplates the use of inserts 37, 38, 39 made of hard metal, these inserts being positioned in apertures or recesses formed in the core adjacent each of the radially extending slots such as the slot 14'. Each of these inserts, such as the insert 38, is thicker than the thickness of the core and projects beyond each of the parallel planar surfaces of the 'core (in much the same By placing the inserts so that one face of each insert is in alignment with a wall of the radial slot, wear of the core at the face of such slot is prevented or greatly minimized so that the full effectiveness and life of the cutting segment 1-7"'is attained. 7 j i The agitating means herein disclosed whether they are inserts, buttons, studs or the'like may be connected to the core in a great'variety of manners as by brazing,

by being press fitted into suitable apertures formed in or adjacent the edge of the core, by being deposited upon the surfaces of the core from suitable welding rods, or by being welded to the surfaces of the core. Stellite, tungsten carbide or other surfacing, facing and hardened cutting metals may be applied. 7

It will thus be understood by those skilled in the art that the action of the agitating buttons 26, 27 deflects cuttings away from the juncture of the core and cutting segment, flushing the cuttings out of the kerf, and thereby minimizing and retarding wear and undercutting of the edge of the core; The spacing of the buttons is such that when the saw is rotated at selected speeds, the area of influence of each button lying behind the button (depending upon direction of rotation) extends to and ineludes the next adjacent button. Thus it will be, understood that the buttons may be positioned centrallybetween the slots or at other points adjacent the edge of the core. Preferably the buttons are positioned in close proximity to the cutting elements so as to flush out cuttings deep in the out being made. Obviously additional buttons may be spaced a selected distance from the cutting element to flush out cuttings which may be contacted thereby. Undercutting of the core about its entire circumference is thus substantially prevented.

It will also be understood that the buttons may be of virtually any shape such as circular, square, rectangular, or triangular as long as they serve to deflect and flush out cut material from the kerf and away from the core.

Other modifications and changes may be made within the spirit of this invention, and all such changes coming within the scope of the appended claims are embraced thereby.

I claim:

1. A circular saw construction including a circular disc-like core of substantially uniform thickness provided with an interrupted edge defined by a plurality of slots extending radially inwardly from said edge; a plurality of cut" ting segments secured to the edge of the core between said slots and projecting from side surfaces of said core; and means carried by the core adjacent and radially inwardly of each cutting segment for agitating and flushing cut material away from said core, said means comprising circumferentially spaced buttons projecting from said side surfaces of the core for approximately but not greater than the same distance as said cutting segments, said buttons being spaced from said slots.

2. A saw construction including a circular disc-like core having side surfaces and. provided with a plurality of slots extending radially inwardly from the circumferential edge of the core; a plurality of cutting segments secured to the edge of the core between said slots and extending outwardly beyond said side surfaces; and means carried by the core adjacent and radially inwardly of each gutting segment, said means including spaced buttons extending from said side surfaces a distance not greater than the projection of said cutting segments therefrom.

3. A saw construction as stated in claim 2 wherein said buttons are made of hardened metal.

4. A saw construction as stated in claim 3 wherein said buttons are made of a resilient material.

5. A saw construction comprising: a core member having side surfaces terminating in a peripheral edge; a plurality of cutting elements carried by the core member at the peripheral edge, each cutting element including metal and diamond particles compressed and sintered together, each cutting element having uniform thickness, of polygonal section, and having side faces outwardly spaced from the side surfaces on said core member; said core member being provided with slots interrupting the peripheral edge between said cutting elements; and hardened elements carried by the core member adjacent the peripheral edge and having an inner edge spaced closer to the center. of the core member than inner edge portions of the cutting elements.

6. A saw construction comprising a circular disc-like core of substantially uniform thickness provided with a plurality of slots extending radially inwardly from the edge of the core; a plurality of arcuate 'cutting elements secured at said edge and disposed individually between said slots and projecting laterally from the planes of the sides of the core; and auxiliary element means carried by and projecting laterally from the planes of the sides of the core to a distance not greater than the planes of the lateral radial sides of the cutting elements, said auxiliary element means being arranged adjacent to at least one radial end of certain of said cutting elements and extending radially inwardly of its respective cutting element for agitating and flushing cut material away from said core.

7. A saw constructionas stated in claim 6 wherein each of said auxiliary element means comprises a hardened element extending across an edge wall of each slot and projecting from the planes of the sides of the core approximately the same distance as the cutting elements.

8. A saw construction as stated in claim 6 wherein said auxiliary element means are spaced circumferentially from said slots.

9. A saw construction as stated in claim 6'wherein said cutting elements include metal and diamond particles compressed and sintered together.

10. A saw construction as stated in claim 6 wherein said auxiliary element means are made of hardened metal.

11. A saw construction comprising a disc-like core of substantially uniform thickness; a plurality of arcuate cutting elements secured to the edge of said core in circumferentially spaced relation and projecting outwardly from the planes of the side surfaces of the core; auxiliary element means carried by the core adjacent to at least one radial end of certain of said cutting elements, said auxiliary element means projecting outwardly from the planes ofthe side surfaces of the core to a distance not greater than the planes of the lateral radial sides of the cutting elements.

12. A saw construction adapted for cutting concrete comprising: a disk-like core member having side surfaces terminating in a peripheral edge; a. plurality of cutting elements carried in a circumferentially spaced relation at the peripheral edge, each cutting element including diamond particles in compressed and sintered powdered metal, each cutting element being 0) polygonal section and of uniform thickness and having a major dimension extending circumferentially of the core member and side faces outwardly spaced from the side surfaces of said core member, said core member being provided with slots interrupting the peripheral edge between said cutting elements; and hardened elements carried by the core member, each hardened element having a face in alignment with'a wall of a slot, and extending from adjacent an inner edge portion of the cutting element toward the center of the core member.

13. A saw construction adapted for cutting concrete comprising: a disk-like core member having side surfaces terminating in a peripheral edge; a plurality of cutting elements carried in circumferentially spaced relation at the peripheral edge, each cutting element including diamond particles in compressed and sintered powdered metal, each cutting element being of polygonal section and of uniform thickness and having a major dimension extending circumferentially of the core member and side faces outwardly spaced from the side surfaces of said core member, said core member being provided with slots interrupting the peripheral edge between said cutting elements and provided with apertures adjacent the peripheral edge; and hardened elements carried by the core member in said apertures, each hardened element having a face in alignment with a wall of a slot, and extending from adjacent an inner edge portion of the cutting element toward the center of the core member.

14. A saw construction adapted for cutting concrete comprising: a disk-like core member having side surfaces terminating in a peripheral edge; a plurality of cutting elements carried in circumferentially spaced relation at the peripheral edge, each cutting element including diamond particles in compressed and sintered powered metal, each cutting element being of polygonal section and of uniform thickness and having a major dimension extending circumferentially of the core member and side faces outwardly spaced from the side surfaces of said core member, said core member being provided with slots interrupting the peripheral edge between said cutting elements, said core member being provided with spaced apertures adjacent the peripheral edge; and hardened elements carried by the core member in said apertures and having an inner edge spaced closer to the center of the core member than inner edge portions of the cutting elements.

15. A saw construction comprising: a core member having side surfaces terminating in a peripheral edge; a plurality of cutting elements carried by the core member at the peripheral edge, each cutting element including metal and diamond particles compressed and sintered together, each cutting element having uniform thickness of polygonal section, and having side surfaces outwardly spaced from the side surfaces on said core member; said core member being provided with slots interrupting the peripheral edge between said cutting elements; and hardened elements carried by the core member adjacent the peripheral edge at walls of said slots and having an inner edge spaced closer to the center of the core member than inner edge portions of the cutting elements.

References Cited in the file of this patent or the original patent UNITED STATES PATENTS 298,353 Crump et a1. May 13, 1884 940,420 Ayers et a1. Nov. 16, 1909 2,064,407 Bird Dec. 15, 1936 2,071,618 Ferrari et a1 Feb. 23, 1937 2,126,382 Goff et a1. Aug. 9, 1938 FOREIGN PATENTS 542,054 Great Britain Dec. 23, 1941 

